sv2v/src/Convert/FuncRoutine.hs

46 lines
1.5 KiB
Haskell

{- sv2v
- Author: Zachary Snow <zach@zachjs.com>
-
- SystemVerilog allows functions to be called without using their result. For
- example, if `f` is a function, one may write `f();` or `void'(f());`, causing
- any side effects of `f` to occur in each case. Verilog-2005 does not allow
- functions to be called as though they were tasks in this way. This conversion
- creates a dummy variable to store the result of the function.
-}
module Convert.FuncRoutine (convert) where
import Control.Monad.Writer
import qualified Data.Set as Set
import Convert.Traverse
import Language.SystemVerilog.AST
type Idents = Set.Set Identifier
convert :: [AST] -> [AST]
convert = map $ traverseDescriptions convertDescription
convertDescription :: Description -> Description
convertDescription (description @ Part{}) =
traverseModuleItems (traverseStmts $ convertStmt functions) description
where functions = execWriter $
collectModuleItemsM collectFunctionsM description
convertDescription other = other
collectFunctionsM :: ModuleItem -> Writer Idents ()
collectFunctionsM (MIPackageItem (Function _ _ f _ _)) =
tell $ Set.singleton f
collectFunctionsM _ = return ()
convertStmt :: Idents -> Stmt -> Stmt
convertStmt functions (Subroutine (Ident func) args) =
if Set.member func functions
then Block Seq "" [decl] []
else Subroutine (Ident func) args
where
t = TypeOf e
e = Call (Ident func) args
decl = Variable Local t "sv2v_void" [] (Just e)
convertStmt _ other = other